1. Field of the Invention
The present invention relates generally to display systems for airplane cockpits or other vehicles, and more particularly, to a rear projection digital display system which allows a high level of information to be selectively displayed regarding such data as travel path, travel conditions, vehicle condition, geographical conditions, and hazard or obstruction warnings.
2. Description of the Related Art
The layouts of cockpits for airplanes are regulated by the FAA in the United States. The SAE (Society of Automotive Engineers), which acts as a standards writing/recommending body to the FAA, has issued standards for aircraft instruments which are adhered to in aircraft construction. For example, the 3ATI slot standard, which is an ARINC (Aeronautical Radio, Inc.) standard, has been complied with in the vast majority of all aircraft in use today. This standard was developed when electromechanical display devices, such as HSI (Horizontal Situation Indicator), were the norm, and only allows a panel area of 3xe2x80x2xc3x973xe2x80x2 in dimension.
With the advance of digital technology, there has been a need in the industry to replace these displays with digital versions, to provide increased reliability, accuracy and more functionality. However, the planes cannot be easily retrofitted with digital equipment that require a bigger screen, and the required 3xc3x973 panel has conventionally proven to be too small for digital displays. The 3xe2x80x3xc3x973xe2x80x3 display has been a major impediment to the development of such a digital display.
First, standard direct view LCDs are not mass produced in this size, and therefore a specially made LCD for 3xe2x80x3xc3x973xe2x80x3 can cost as much as $10,000 each to produce. Furthermore, due to the construction of the direct view LCD, the outer perimeter of the device cannot be used to display information, as it is used by the drive electronics. As a result, the 3xe2x80x3xc3x973xe2x80x3 LCD typically produces a display area of only 2.3xe2x80x2xc3x972.3xe2x80x2. This reduced display area impedes the ability to put enough information on the display for it to be useable for many functions.
A second problem addressed by the invention is the growing demand in the avionics industry for more sophisticated xe2x80x9csituational awareness for safetyxe2x80x9d (SAS) technology. This refers to technology which provides the pilot with more easily understandable and more comprehensive information about the immediate surroundings, and any hazards which may be present.
For example, in 1996, there were 246 general aviation airplane crashes in the United States. Of these crashes, 42 were controlled flight into terrain (CFIT). That is, situations in which the airplane was flown into an obstruction such as a mountain, an antenna or the ground under control of the pilot. Typically these instances occur when visibility is very low and the pilot is off course. As a result, the pilot is unaware of the natural obstructions in the flight path because the display devices only provide information on the desired flight course.
It is believed that if the present invention had been available for these planes, a large number of these accidents would have been prevented, and hundreds of lives saved. Thus, there is a need in the industry for (1) technology to effectively collect data on surrounding structures even when the pilot is off path, and (2) hardware to display this information in a simple and direct manner to the pilot, preferably using digital instruments.
Accordingly, it is an object of the present invention to overcome the above-noted deficiencies in the prior art.
In particular, in certain aspects of the invention, an avionics display device may include a rear projection LCD system which obtains maximum display area in a 3ATI display slot.
In addition, in the present invention the microprocessor may receive G.P.S. (xe2x80x9cGlobal Positioning Systemxe2x80x9d) data as an input, and may also have a memory which stores topographical map data (e.g., Defense Mapping Agency topographical information of North America or other geographical area) in database form. The device correlates the G.P.S. and topographical data to determine the location of the aircraft, and any obstacles in the flight path or surrounding area. Other navigational devices (e.g. VOR) may also be used to determine position. In addition, data from the flux gate and gyro may be used to aid in the determining the flight path of the aircraft. From this information, upcoming obstacles are determined from the DOD topographical data and are displayed to the pilot.
In certain embodiments of the invention, different types of information are selectively displayable on the system. To avoid clutter and ease of understanding, user inputs are provided to allow the pilot to selectively turn on or off the display of certain information. For example, as the pilot is approaching the runway for a landing, and is within visible range of the runway, the pilot may turn off the rearward view or navigational aids not associated with the approach to the runway.
In addition, it should be noted that while the present invention is a well-suited for use in the avionics cockpit display, it is equally applicable to other vehicles.